2.1. Supported architectures

The following are the officially supported architectures for Debian
8:

32-bit PC ('i386') and 64-bit PC ('amd64')

64-bit ARM ('arm64')

ARM EABI ('armel')

ARMv7 (EABI hard-float ABI, 'armhf')

MIPS ('mips' (big-endian) and 'mipsel' (little-endian))

PowerPC ('powerpc')

64-bit little-endian PowerPC ('ppc64el')

IBM System z ('s390x')

Three architectures which were part of Debian 7 are not released
with jessie.

As announced when Debian 7 was released, the 32-bit s390 port is discontinued and replaced with
s390x.

In addition, the ports to IA-64 and Sparc had to be removed from this release
due to insufficient developer support. Sparc had been a supported architecture
in Debian since 2.1 (1999), while ia64 was
introduced in Debian 3.0 (2002).

Finally, the Debian ports to the FreeBSD kernel, kfreebsd-amd64 and
kfreebsd-i386, included as technology previews in Debian 6.0 and Debian 7, are
not part of this release.

You can read more about port status, and port-specific information for your
architecture at the Debian port
web pages.

2.2. What's new in the distribution?

This new release of Debian again comes with a lot more software than
its predecessor wheezy; the distribution includes over
12253 new packages, for a total of over 43512
packages. Most of the software in the distribution has been updated:
over 24573 software packages (this is
66% of all packages in wheezy).
Also, a significant number of packages (over 5441,
14% of the packages in wheezy) have
for various reasons been removed from the distribution. You will not
see any updates for these packages and they will be marked as
'obsolete' in package management front-ends; see Section 4.10, “Obsolete packages”.

Debian again ships with several desktop applications and
environments. Among others it now includes the desktop environments
GNOME
3.14, KDE
4.11, Xfce 4.10, and
LXDE.

Productivity applications have also been upgraded, including the
office suites:

LibreOffice
is upgraded to version 4.3;

Calligra
is upgraded to 2.8;

GNUcash is upgraded to 2.6;

GNUmeric is upgraded to 1.12;

Abiword is upgraded to 3.0.

Updates of other desktop applications include the upgrade to
Evolution 3.12.

Among many others, this release also includes the following software updates:

Package

Version in 7 (wheezy)

Version in 8 (jessie)

Apache

2.2.22

2.4.10

BINDDNS Server

9.8

9.9

CourierMTA

0.68

0.73

Dia

0.97.2

0.97.3

Exim default e-mail server

4.80

4.84

GNU Compiler Collection as default compiler

4.7 on PCs, 4.6 elsewhere

4.9

the GNU C library

2.13

2.19

lighttpd

1.4.31

1.4.35

Linux kernel image

3.2 series

3.16 series

OpenLDAP

2.4.31

2.4.40

OpenSSH

6.0p1

6.7p1

Perl

5.14

5.20

PHP

5.4

5.6

PostfixMTA

2.9

2.11

PostgreSQL

9.1

9.4

Python 3

3.2

3.4

Samba

3.6

4.1

2.2.1. CDs, DVDs, and BDs

The official Debian distribution now ships on 9 to 10 binary
DVDs
or 75 to 85 binary CDs
(depending on the
architecture) and 10 source DVDs or 59 source
CDs. Additionally, there is a
multi-archDVD, with a subset
of the release for the amd64 and
i386 architectures, along with the source
code. Debian is also released as Blu-ray
(BD) images, 2 each for the
amd64 and i386 architectures, or
2 for the source code. For size reasons, some very large packages
are omitted from the CD builds; these packages fit
better in the DVD and BD builds,
so are still included there.

2.2.2. Changes in the GNOME desktop

Being upgraded to version 3.14, the new GNOME desktop brings many new
features and usability improvements.

The design of the GNOME shell has been updated. The bottom message tray
is larger, easier to use and less prone to appear accidentally. A new
system status area in the upper right corner puts all useful settings
in the same place.

The screensaver has been replaced by a "lock screen" that still brings
minimal functionality when the user is away. For example, you can pause
the music, be informed of a new e-mail, or change the screen brightness,
all of that without entering a password. Pressing the Escape key or
starting to type the password brings back the login prompt. The GNOME
display manager uses the exact same design for consistency.

Several applications, including the Nautilus file manager, the gedit
text editor, and the evince document viewer have seen their design made
much more compact, merging the window titlebar with the toolbar. This
leaves much more room for the documents the user is working on. The
standard dialog boxes have undergone similar changes.

Support for touch screens has been fully integrated, including intuitive
gestures based on multiple finger movements. GNOME now also supports
high resolution (HiDPI) screens, taking full advantage of fine pixeling
for the clearest rendering.

GNOME supports geolocation, and includes a smooth mapping and navigation
application.

The user documentation is much more complete, and includes video tutorials
for new users.

2.2.3. New default init system (systemd)

Introduced in Debian 7, systemd is now the default init system. It
provides advanced monitoring, logging, and service management capabilities.

While it is designed as a drop-in
sysvinit replacement and as such
makes use of existing SysV init scripts, the
systemd package can be installed
safely alongside sysvinit and
started via the init=/bin/systemd kernel option. The
systemd-sysv package provides the
/sbin/init replacement.

2.2.4. Security

The legacy secure sockets layer protocol SSLv3 has been
disabled in this release. Many system cryptography libraries as well
as servers and client applications have been compiled or configured
without support for this protocol.

The Linux kernel features a security mechanism which nullifies many
symlink attacks. It is enabled in the Debian Linux kernel by default.
/tmp-related bugs which are rendered non-exploitable by this
mechanism are not treated as security vulnerabilities. If you use a custom
Linux kernel you should enable it using a sysctl setting:

echo 1 > /proc/sys/fs/protected_symlinks

In some rare cases the security support for a package shipped in
a Debian release needs to be terminated prior to the end of support
for the full distribution. Jessie provides a new package (debian-security-support) which emits a warning
if support for a package needs to be terminated in advance. It also
documents packages where the scope of security support is limited.
As such, it is recommended to install debian-security-support on
all security-relevant systems.

Continuing on the path set by Wheezy, more packages
have been built with hardened compiler flags. Also, the stack
protector flag has been switched to stack-protector-strong for extra
hardening. Note that the hardened build flags are not enabled by
default in gcc, so they are
not used automatically when locally building software.

New in this release is the needrestart package. When installed, it
will perform a check after each APT upgrade session. If any
services running on the system require a restart to take advantage
of changes in the upgraded packages then it offers to perform these
restarts. It is recommended to install needrestart to ensure that security
updates in libraries are propagated to running services.

2.2.5. MariaDB next to MySQL

Along with the older MySQL 5.5, Jessie ships the new MariaDB 10.0.
See the Debian MySQL Team
wiki page for more information. Only one of them is likely to be
included in Debian 9.

Note that upstream support for MySQL 5.5 will cease in December
2018 (and Debian security support will have to follow that), while
MariaDB 10.0 will receive upstream security support until March
2019.

2.2.6. PHP applications

The Horde Application Framework is available in Jessie, via
the php-horde package.

2.2.7. Debian Games Blend

The Debian Games Team proudly presents the Debian Games Blend consisting of
33
metapackages which simplify the installation of games per
category. The selection includes among many others strategy, simulation, card,
and programming games. Debian Games also offers developers a quick way to
install recommended software for developing games in the C++, Java, Perl, or
Python 3 programming languages. Content developers will find useful tools
for creating game art in games-content-dev.
The project homepage provides screenshots and further information and
offers a compact overview about all games including
Debian's finest games.

2.2.8. News from Debian Med Blend

The Debian Med team has again considerably increased not only the number
of packages in the fields of biology and medicine but also their quality in
terms of testing (at package build time as well as autopkgtest). These
enhancements in version 2.0 of the Debian Med Blend metapackages reflect the
demand from scientists for reliable software to provide reproducible results.
Visit the Debian Med tasks
pages to see the full range of biological and medical software in
Debian.

2.2.9. News from Debian Science Blend

Due to the continuous work of the Debian Science team not only new
scientific applications were added to the Debian package pool but also
new fields of science are covered by certain applications.
Visit
Debian Science tasks pages
to see the full range of scientific software inside Debian.

2.2.10. News from Debian Geographical Information Systems (GIS) Blend

During the jessie development cycle many changes from
UbuntuGIS were merged back into Debian GIS. The collaboration
with UbuntuGIS and OSGeo-Live projects was improved, resulting in
new packages and contributors. Visit Debian GIS tasks
pages to see the full range of GIS software inside Debian
and the Debian GIS
homepage for more information.

2.2.11. News from the Debian Java Team

Jessie ships with 799 source packages (442 updated, +130 new ones since
Wheezy) which will be maintained by the
Java Team. Notable changes: